I don't like it that I can only select the numbers in "r123456", and the jagginess of user-select:all is unpleasant.
Not sure if there were some deep reasons for such behavior. Let me propose a patch to see if there is something I overlook.
Created attachment 220005 [details]
Not really. My fault, I thought it would be cute (and I was repairing the user-select:none that was already there). But you're right, it's not great.
Comment on attachment 220005 [details]
Clearing flags on attachment: 220005
Committed r161078: <http://trac.webkit.org/changeset/161078>
All reviewed patches have been landed. Closing bug.